No Common sense nor logic. Absolutly shocking experience!!!

I bought my wife a stunning pair of shoes as a Christmas present on 5 December. She opened them on Christmas Day as you do and loved them, but they don't fit her. We left for our vacation on 27 December and only returned 8 December. I now want to exchange for a bigger size which they don't have so a refund / credit would also suffice. I received a message which states that the 30 Day period for return is expired. We have been away on holiday since after Christmas until after the 5 of January (30 day period) When exactly was i supposed to return these shoes? I have offered to submit proof of travel documents but they have made their mind up and are refusing to look into the matter. This is absolutely ridiculous!!!!